Separating flexibly rolled strip material

ABSTRACT

Separating flexibly rolled strip material can include a buffer device for temporarily storing the flexibly rolled strip material; a first feed device behind the buffer device; at least one length measuring device for continuously measuring a length of the strip material; a thickness measuring device for continuously measuring a thickness of the strip material along the length; a second feed device behind the first feed device; a separating device behind the second feed device; the first and second feed devices being configured to move the strip material from the buffer device to the separating device depending on the thickness measurement and the length measurement; the thickness measuring device being arranged between the buffer device and the first feed device; and the length measuring device being arranged behind the first feed device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of, and claims priority to, Patent Cooperation Treaty Application No. PCT/EP2019/061408, filed on May 3, 2019, which application claims priority to European Application No. EP18171364.5, filed on May 8, 2018, which applications are hereby incorporated herein by reference in their entireties.

BACKGROUND

From CN 104551538 B a device and a method for separating flexibly rolled strip material are known. The strip material is fed from a coiler to a strip accumulator via a first clamping roller and a strip straightening arrangement. Behind the strip accumulator there are two further clamping rollers with integrated length measurement, between them a strip thickness measurement, and behind them a hydraulic shear for separating the strip material. The first clamping roller determines the strip length fed to the strip accumulator and the clamping roller arranged behind the strip accumulator determines the strip length fed out of the strip accumulator. By integrating the difference between the fed-in strip length and the fed-out strip length over time, the strip length stored in the strip accumulator can be determined. If the stored strip length in the strip accumulator exceeds a nominal value, strip material is fed via the clamping roller arranged behind the strip accumulator and the subsequent thickness measuring unit, and an actual thickness profile of the strip material is determined. Based on the actual thickness profile, a cutting plan is determined according to which the fed length of the strip material is controlled and the cutting process is carried out. The strip length fed to the hydraulic shear is determined by averaging the values determined by the clamping rollers arranged immediately before and behind the thickness measurement.

From EP 3 181 248 A1 a process and an apparatus for producing a sheet metal blank are known. The method includes the steps: flexible rolling of a strip material, wherein a thickness profile with different sheet thicknesses is produced over the length of the strip material; determining a measuring thickness profile of several regions of the strip material lying one behind the other; calculating a desired position in the strip material for a sheet blank to be cut from the strip material as a function of the generated measuring thickness profile of at least two regions of the strip material lying one behind the other; cutting the flexibly rolled strip material by at least one cutting device along the desired position for producing the sheet blank.

The production of shaped cuts and rectangular blanks, also known as Tailor Rolled Shapes or Tailor Rolled Blanks, can be carried out using a suitable separating device. For this purpose, the strip feeding device arranged in front of the cutting device is equipped with a decoiler, a straightening machine, a strip buffering unit and a feeding device. The threading of a metal strip into such an apparatus is done manually by the operator. The operator threads the beginning of the strip up to a marked position in the cutting tool or on the cross-cutting shear. The automatic mode is then started and the feed system feeds the strip forward by a predetermined length per working stroke, which is always the same. With this procedure, the cyclic thickness profile of the flexibly rolled strips can only be positioned inaccurately or not at all to the separating edge of the cutting device. This means that position tolerances for the thickness profile relative to the position within the contour cut or the rectangular blank cannot be fulfilled. In addition, areas of the metal strip that do not comply with the thickness tolerances cannot be detected and sorted out. Furthermore, it is not possible to position cyclically recurring thickness profiles in the flexibly rolled strips automatically and precisely on the cutting edges of the cutting devices.

SUMMARY

Disclosed herein is an apparatus and a method for separating flexibly rolled strip material. Flexibly rolled strip material has a variable thickness profile in the longitudinal direction of the strip. The separation of flexibly rolled strip material therefore requires exact positioning of the separation region in order to obtain blanks with a defined nominal thickness profile. Disclosed herein is a apparatus for separating flexibly rolled strip material, which enables precise measurement and evaluation of sheet thickness profiles and ensures precise positioning of the strip material for separation. Further disclosed is an appropriate process for separating flexibly rolled strip material that will allow accurate measurement, evaluation and positioning.

An apparatus for separating flexibly rolled strip material is disclosed, comprising: a buffer device for temporarily buffering the flexibly rolled strip material; a first feed device arranged behind the buffer device in the feed direction of the strip material; at least one length measuring device for continuously measuring a length of the strip material; a thickness measuring device for continuously measuring a thickness of the strip material along the length; a second feed device arranged behind the first feed device; a separating device arranged behind the second feed device in the feed direction of the strip material; wherein the first feed device and the second feed device are arranged to move the strip material from the buffer device to the separating device depending on the thickness measurement and the length measurement; wherein the thickness measurement device is arranged in the feed direction of the strip material behind the buffer device and in front of the first strip feed device; and the at least one length measurement device is arranged in the feed direction of the strip material behind the first strip feed device.

The apparatus has the advantage that the feed applied by the first feed device can be controlled on the basis of the values previously determined by the thickness measuring device. A recurring thickness profile of the flexibly rolled strip can be precisely detected, compared with the desired target profile and positioned exactly in the separation position of the separating device. In addition, areas of the metal strip that do not comply with the thickness tolerances can be identified and sorted out.

According to an embodiment, the apparatus can have a coiler for uncoiling the flexibly rolled strip material and at least one straightening unit for straightening the flexibly rolled strip material. Several straightening units can be used in particular for processing particularly thick strips and/or for strips with large absolute thickness increments of, for example, more than 1 mm. The coiler and the at least one straightening unit, which together can also be referred to as the uncoiling and straightening group, are connected upstream of the strip buffer device. Preferably, the first and second feed devices for the separating device are independently controlled from of the feed of the uncoiling and straightening group. The uncoiling and straightening group conveys the strip into the strip accumulator and makes the flexibly rolled strips available for processing by the further apparatus. The conveying respectively uncoiling speed of the uncoiling and straightening group can be controlled by a filling level sensor of the strip accumulator. For example, the filling level sensor can be an ultrasonic unit that senses the depth of the strip loop hanging in the strip accumulator and transmits a corresponding signal to the controller for the uncoiling and straightening group. It is to be understood that other sensors can also be used, such as an optical sensor, a capacitive sensor and/or an inductive sensor. The straightening unit can be supported by an infeed driver and a take-off roller. The operation or running of the coiler, inlet driver, straightening unit and take-off roller can be synchronized with each other via controllers and can be operated in speed control or torque control to each other. Each of the units can be operated individually, i.e. independently of the others, as a generator or motor. The embodiment with decoiler and straightening group is suitable when the strip material is rewound into a coil after flexible rolling and further processed elsewhere. In principle, however, it is also possible that the strip accumulator, feed and separation unit directly follow a flexible rolling in the continuous process.

The strip accumulator serves to decouple the uncoiling and straightening group of the apparatus from the position-controlled part of the apparatus which operates on the basis of feed lengths, with the components thickness measurement, feeds, length measurement and separating device. In particular, it is provided that the length-based feed control of the separating unit is based only on the length measurement values of the length measuring device located behind the strip accumulator. Any measured length values measured before the buffer device can be ignored by the feed control in this case.

The thickness measuring unit is arranged in feed direction behind the strip buffer and in front of the first feed device. The corresponding first length measuring unit is located directly behind the first feed device. The first length measuring unit is designed to continuously measure the length of the strip material. Thickness measurement is also carried out continuously during the strip feed. Preferably the length measuring device and the thickness measuring device are coupled with each other in a measurement technical manner. It is provided in particular that the length measuring unit generates trigger signals and transmits them to the thickness measuring unit in order to trigger thickness measurements, which are then recorded.

According to an embodiment, the length measuring unit may include a measuring wheel which is in contact with the first side of the strip material, and a support wheel which is in contact with an opposite side of the strip material as a counter bearing for the measuring wheel. The running surface of the measuring wheel can, for example, be made of a steel material. The running surface of the support wheel can, for example, be made of an elastic material. It is to be understood that the design of the length measuring unit described above can also be used for any other length measuring unit in the apparatus.

According to a preferred embodiment, two length measuring devices are provided, a first length measuring device which is assigned to the first feed device, and a second length measuring device which is assigned to the second feed device. The second length measuring device is arranged in the feed direction of the strip material after the second feed device and before the separating device. For a high measuring accuracy it is advantageous if the measuring devices are arranged as close as possible to the respective feeds. Preferably the first length measuring device has a first distance to the first feed device which is smaller than 0.5 times, in particular smaller than 0.25 times, the distance between the first feed device and the second feed device. The second length measuring device may have a second distance from the second feed device which is smaller than 0.5 times, in particular smaller than 0.25 times, the distance between the second feed device and the separating device.

The two feed devices work synchronously to feed the strip material from the strip accumulator to the separating unit. Both feeds exert a tensile force to the strip material to move it. To ensure that the strip material is kept flat between the two feed devices, the second feed device, which is located downstream in the feed direction, may be driven in particular faster than the upstream first feed device. In this way, the strip material between the two feed devices is held slightly in tension and is thus flat, which has a positive effect on the measured value accuracy.

According to a preferred embodiment, the distance between the thickness measuring device and the separating device is at least twice the blank length of a blank to be cut from the strip material. In particular, the distance is at least twice the length of a blank plus the feed path covered by the strip material during the computing time for a blank to be cut.

The separating device can be selected according to the requirements of the flat product to be separated and can comprise, for example, a cross-cutting shear or a beam cutting unit, in particular a laser cutting unit. For simply cutting to length of blanks, a cross-cutting shear, a cross-cutting laser or a comparable beam system for cross-cutting can be used in conjunction with the strip feed system. For producing shaped cuts, a press line with suitable cutting tools or a beam cutting unit, in particular a laser beam unit, can be used which in each case are connected to the strip feed apparatus.

A solution to the above object further is a process for separating flexibly rolled strip material, in particular by an apparatus according to any one of the above embodiments, comprising the steps: buffer storing the flexibly rolled strip material by a buffer device; feeding the strip material from the buffer storage by a first feed device and a second feed device; continuously measuring a thickness of the strip material by a thickness measuring device while the strip material is being advanced, with the thickness being measured in the feed direction of the strip material upstream of the first feed device; continuously measuring a length of the strip material by a length measuring device while the strip material is being advanced, with the length being measured in the feed direction of the strip material downstream of the first feed device; calculating an actual thickness profile for a blank to be separated from the strip material from measured thickness values and associated measured length values; comparing the calculated actual thickness profile with a predetermined nominal thickness profile and calculating a feed length for the blank to be separated from the strip material; feeding the strip material to a separating device by the first feed device and the second feed device on the basis of the calculated feed length.

The length measurement behind the respective feed unit decouples the feed movement from the length measurement, which leads to particularly accurate measurement results. The thickness measurement before the first feed unit also has a positive effect on the measuring accuracy, since the feed applied by the first feed unit can be controlled by means of the values previously determined by the thickness measuring unit. The use of the second position-controlled feed device with associated length measuring unit contributes to a flat, warp-free and loop-free strip run between the thickness measuring unit and the cutting point, which in turn ensures precise positioning of the reference edges of the feed lengths in relation to the cutting point. The advantages for the process as a whole are the same as for the apparatus. A recurring thickness profile of the flexibly rolled strip can be precisely detected, compared with the desired target profile and positioned exactly relative to the separation point of the separating device. In addition, areas of the metal strip that do not comply with the thickness tolerances can be identified and sorted out. It is understood that all procedural features can be applied analogously to the apparatus and vice versa, all apparatus-related features can be applied to the process.

According to a method embodiment, the strip material is pulled out of the strip buffer storage by the position-controlled first and/or second strip feed. The flexible rolled strip is continuously measured with respect to thickness by the thickness measuring unit. On the basis of the measured thickness and taking into account the corresponding measured length values, the thickness measuring unit evaluates whether the flexible rolled strip corresponds to the required thickness tolerances or not. The comparison of the determined actual thickness profile with the predefined target thickness profile is carried out in particular taking into account the associated tolerances of the target thickness profile, which can be represented by an envelope curve. Thereby, it is examined whether the determined actual profile lies within the envelope of the target profile. From the result of the comparison, the feed length for the strip respectively the blank to be cut therefrom, and the cutting position of the blank in the strip can be calculated. The strip is divided into areas that are OK (so-called OK parts) and areas that are not OK (so-called not OK parts). The position and length of these individual regions in the strip is transferred from the thickness measuring device to the first feed device. The first feed device, and also the second feed device coupled to it, can then carry out the feeds instructed by the thickness measuring unit and position the reference edges of the individual feed lengths precisely at the cutting point of the cutting device. The feed unit can pass on the information to the other system components as to whether the feed length is a length with OK thickness profile or not OK thickness profile.

The length measuring device is designed to continuously measure a length value representing the feed path of the strip. Preferably, high-precision length measuring devices are used which have a measuring tolerance of up to 0.5 mm per metre strip length, in particular of up to 0.1 mm per metre strip length. The length can be measured, for example, by means of a measuring wheel which is in contact with the passing strip material. The length measuring device can measure the strip material from beginning to end without interruption. The starting point of the measurement can be the beginning of the strip, which defines the zero position of the length accordingly. From the starting point of the length measurement, the length is continuously measured.

According to a preferred method embodiment, the first length measuring device of the first feed is referenced at the starting point with the thickness measurement with regard to the length. This can be done by continuously transmitting the measured length value from the first length measuring device to the thickness measuring device. The length measured values can be indicated either absolutely or incrementally. The thickness measurement scales the thickness measurement values based on the indicated length measurement values along the strip length. In this way, both measuring instruments can work from exactly the same strip length zero point. The measured actual thickness profile can be reliably compared with the specified nominal thickness profile and a corresponding evaluation can be made with regard to the parts that are OK and those that are not. The referencing of the length measuring device with the thickness measuring device is also important for the position-accurate positioning of the feed lengths by the feed device in relation to a reference cutting position for separating. Alternatively or in addition, the second length measuring device of the second feed can be referenced at the starting point with the thickness measurement with regard to the length.

According to an embodiment, a further length measurement of the strip material can be carried out by a second length measuring device during the feeding of the strip material to the separating device, wherein the length measuring by the second measuring device is carried out in the feed direction of the strip material behind the second feed device. It may also be provided as a further process step: comparing the first measured length values determined by the first length measuring device with the associated second measured length values determined by the second length measuring device; and switching off the apparatus if a difference between the first measured length values and the second measured length values exceeds a predetermined difference value. This embodiment provides a measurement redundancy so that the risk of outage parts is reduced.

According to a method embodiment, a fixed distance can be set between the thickness measuring device and the first feed device. This distance is measured precisely, preferably with an accuracy of up to +/−0.2 mm (millimeters), and maintained during operation of the apparatus. In this way, the length reference between the thickness measurement on the one hand and the feed respectively length measurement on the other hand can be reliably guaranteed over the entire length of the strip material.

For the precise positioning of a reference edge of a feed length to a reference separating position of the separating device, a fixed distance can be set between the thickness measuring device and the separating device according to a possible embodiment. This distance is measured precisely, preferably with an accuracy of up to +/−0.2 mm, and is maintained during operation of the apparatus.

According to a further method embodiment, the measuring distance between the thickness measurement and the separating device can be set to at least twice the blank length of a blank to be cut out of the strip material. In particular, the distance between the thickness measurement and the separating device can be set to at least twice the length of a blank plus the feed path covered by the strip during the computing time for a blank to be cut.

As far as reference is made in this disclosure to a distance between two devices, this may refer to a given reference point of the respective device, e.g. a measuring plane at the measuring devices, or a separation point at the separating device.

According to a preferred method embodiment, the second feed device is operated synchronously with the first feed device, in particular with the same length scale as the first feed device and the thickness measuring unit. By controlling in a manner that the second feed unit advances slightly relative to the first feed unit, the second feed unit generates a light strip tension in the strip section located within the measuring path, which ensures a flat strip run.

BRIEF SUMMARY OF THE DRAWINGS

Embodiments are explained below using the drawing figures. Herein:

FIG. 1 shows an exemplary apparatus for separating flexibly rolled strip material schematically in three-dimensional representation in a first embodiment;

FIG. 2 shows a process for separating flexibly rolled strip material;

FIG. 3 shows the thickness profile of an exemplary blank that can be produced with the apparatus and process shown in FIGS. 1 and 2;

FIG. 4 shows the thickness profile of another exemplary blank that can be produced with the apparatus and process described in FIGS. 1 and 2;

FIG. 5 shows the thickness profile of another exemplary blank that can be produced using the apparatus and process shown in FIGS. 1 and 2;

FIG. 6 shows an exemplary sequence of several blanks according to FIG. 3 or FIG. 4;

FIG. 7 shows an exemplary apparatus for separating flexibly rolled strip material schematically in three-dimensional representation in a second embodiment;

FIG. 8 shows an exemplary contour cut in top-view, which can be produced with the apparatus according to FIG. 7 and the process according to FIG. 2, respectively;

FIG. 9 shows an exemplary sequence of several contour cuts as shown in FIG. 8.

DESCRIPTION

FIGS. 1 through 9 are described jointly below. FIG. 1 shows an exemplary apparatus 2 for separating flexibly rolled strip material 3. Flexible rolled strip material means that a strip material with a substantially constant sheet thickness is rolled along its length by rollers in such a way that it obtains a variable sheet thickness along the rolling direction. After flexible rolling, the strip material has 3 different thicknesses over its length in the rolling direction. After flexible rolling, the strip material 3 is coiled-up to a coil 4 so that it can be fed to the next process step, or it can be further processed directly if applicable.

A coil 4 of flexible rolled strip material is shown as starting material. The apparatus 2 comprises a coiler 5 for uncoiling the flexibly rolled strip material 3 and a straightening unit 6 for straightening the flexibly rolled strip material. The straightening unit 6 comprises a plurality of rolls, in particular between 7 and 23 rolls, which the strip material passes through. Between the coiler 5 and the straightening unit 6 an infeed driver 7 can be provided, which pulls the strip material 3 from the coiler and feeds it to the straightening unit. A take-off roller 8 can be arranged behind the straightening unit 6 in the feed direction of the strip, which transmits a feed force to the strip material 3. The operation of the apparatus components coiler, infeed driver, straightening unit and take-off roller can be synchronized with each other via controllers and operated in speed control or torque control to each other. Each of the units can be operated individually, i.e. independently of the others, as a generator or motor. FIG. 1 shows the moments M5, M6, M7, M8 that can be transmitted from the respective components 5, 6, 7, 8 to the strip material.

In the strip feed direction behind the uncoiling and straightening group 10, a buffer device 9 is provided, which is designed to temporarily store a respective section of the strip 3. A feed movement of the uncoiling and straightening group 10 is decoupled from a feed movement of the separating group 12. The uncoiling and straightening group 10 conveys the strip 3 into the strip buffer storage 9, which makes the flexibly rolled strip 3 available for further processing in the separating group 12. The conveying respectively uncoiling speed of the uncoiling and straightening group 10 can be controlled by a level sensor 13 of the strip buffer storage 9. The level sensor 13 can, for example, include an ultrasonic sensor or an optical sensor which senses the depth of the strip loop hanging in the strip accumulator and transmits a corresponding signal to the controller for the uncoiling and straightening group 10.

The apparatus 2 comprises as further components behind the buffer device 9 a thickness measuring device 14 for continuous measurement of the thickness of the strip material, a first feed device 15, a first length measuring device 16 associated with the first feed device for continuous measurement of the length of the strip material 3, a second feed device 17 which is arranged at a distance behind the first feed device 15, a second length measuring device 18 associated with the second feed device 17 and a separating unit 19 for separating the strip material 3.

The two feed devices 15, 17 are operated synchronously and are designed to move the strip material 3 from the buffer device 9 to the separating device 19 depending on the thickness measurement and the length measurement. The two feeds 15, 17 each exert a feed force on the strip material in order to move it. In order to keep the strip material flat between the two feed devices 15, 17, the second feed device 17 can be driven with a slight advance compared to the first feed device 15. A special feature of the present arrangement is that the thickness measuring device 14 is arranged in the feed direction R of the strip material 3 behind the buffer device 9 and before the first feed device 15, and that the first length measuring device 16 is separate from the first feed device 15 and is arranged downstream thereof. For the length-based feed control of the separating group 12, only the length measuring values of the length measuring devices 16, 18 located behind the strip buffer 9 are used as a basis.

The first length measuring device 16 and the thickness measuring device 14 are coupled with each other with respect to measurement technique. A fixed distance A1 is set between the thickness measuring device 14 and the first feed device 15 in order to reliably maintain the length reference over the strip length between the thickness measurement device 14 on the one hand and the first feed device 15, respectively the first length measurement device 16, on the other hand. This distance A1 is measured precisely, preferably with an accuracy of up to +/−0.2 mm, and maintained during operation of the apparatus. In this way, the length reference between the thickness measurement on the one hand and the feed respectively length measurement on the other hand can be reliably guaranteed over the entire length of the strip material. During operation of apparatus 2, the length measuring unit 16 can generate trigger signals B1 and transmit them to the thickness measuring unit 14. Each trigger signal B1 serves as a trigger for a thickness measurement, so that with each trigger signal of the length measuring unit 16 a thickness measurement value is generated and assigned to a corresponding length measurement value. In this way, data records are generated from pairs of length and thickness values, from which the actual thickness profile of the blank to be cut from strip material 3 can be determined.

The first and second length measuring units 16, 18 each comprise a measuring wheel 20, 20′, which is in contact with a first side of the strip material 3, as well as a support wheel 21, 21′, which serves as a counter bearing for the measuring wheel 20, 20′. The running surface of the measuring wheels can, for example, be made of a steel material. The running surface of the support wheels, for example, can be made of an elastic material. It is to be understood, however, that other forms of length measurement, such as non-contact sensors, can also be used. For a high measuring accuracy of the measured length values, it is advantageous if the measuring devices 16, 18 are arranged as close as possible to the respective feeds 15, 17. In particular, the distance between the first length measuring device 16 and the first feed device 15 may be less than 0.1 times the distance between the two feed devices 15, 17. The distance between the second length measuring device 18 and the second feed device 17 may be less than 0.1 times the distance between the second feed device 17 and the separating device 19.

FIG. 1 further shows the distance A2 between the thickness measurement device 14 and the separating device 19. This is preferably at least twice the blank length L22 of a blank 22 to be cut out of the strip material 3 plus the feed path which the strip material covers during the calculation time for a blank to be cut out.

The separating device 19 can be selected according to the requirements of the flat product 22 to be separated and can, for example, comprise a mechanical separating device, such as a cross-cutting shear (as shown here), or a beam cutting unit, in particular a laser cutting unit. In general, the separating device can also be described as a cutting or parting device. The present cutting device 19 is designed to produce cuts perpendicular to the strip edge. It is to be understood, however, that the separating device can also be adapted to the final contour of the blank to be produced with regard to the separating cut to be performed. For example, the cutting device can also be designed to produce cuts that run diagonally to the strip edge, or curved cuts. In this way, as the case may be, the amount of scrap may be reduced.

Hereinafter, a method for separating flexible rolled strip material 3 into blanks 22 is described with reference to FIG. 2. The method can be considered in two parts with regard to the controlling of the components. This is because the process steps S10 of uncoiling and S20 of straightening, that are carried out by the uncoiling and straightening group 10, can be decoupled with regard to control technique from the process steps (S40-S130) that are carried out behind the strip buffer store S30 by the feed and separating group 12, at least with regard to the feed of the strip material.

Step S30 provides for temporarily buffering the flexible rolled strip material 3 by the buffer device 9. In particular, it is provided that the strip material 3 is continuously fed from the uncoiling and straightening group 10 into the strip buffer device 9. In step S40, the strip material 3 is fed out of the temporary buffer store 3 by the first and second feed devices 16, 17. This is done in particular at intervals according to a calculated feed length for the blank 22 to be cut out of the strip material 3 in each case. To determine the feed length, a continuous measurement of a thickness signal and a length signal of the strip material 3 is carried out in steps S50, S60. This is carried out continuously by the thickness measuring device 14 and the first length measuring device 16, i.e. while the strip material 3 is moved by a feed length by the feed devices 15, 17. The thickness measurement (S50) is carried out in the feed direction R of the strip material 3 before the first feed device 15 and/or before the first length measuring device 16.

The thickness and length values measured by the measuring devices 14, 16 are transmitted to a calculation or control unit, respectively, where they are further processed to calculate the actual thickness profile of a blank 22 to be cut and to calculate the feed length for this blank. To determine the thickness profile of the strip, respectively the blanks to be cut therefrom, a thickness value D is assigned to each length position L of strip material 3. Since the thickness measuring device 14 is arranged before the first feed device 15, the thickness values measured by same and the actual thickness profiles determined therefrom together with the corresponding length values can be taken into account directly in the current feed movement. The length measurement can be carried out in the feed direction R of the strip immediately behind the first feed device 15.

The continuous measurement of the length, respectively path signal of the strip material 3 by the first length measuring device 16 takes place simultaneously with the thickness measurement while the strip material is being advanced. In particular, it is provided that the first length measuring device 16 be referenced at the starting point with the thickness measuring device 14 with regard to length. This is done for the first time, as described above, by setting the defined distance dimension A1, as well as during the process by continuously communicating the measured length value from the first length measuring device 16 to the thickness measuring device 14. The communicating of the measured length values can be absolute or incremental, for example by trigger signals B1, B2. The thickness measurement scales the thickness measurement values using the communicated length measurement values over the strip length. In this way, both measuring devices 14, 16 work from exactly the same strip length zero point. In step S70, the actual thickness profile for the blank 22 to be separated from the strip material 3 is calculated from the measured thickness and length values of the measuring devices 14, 16. The measured actual thickness profile can be reliably compared with the specified nominal thickness profile and the associated tolerances, in particular represented by an envelope curve, in step S80 and a corresponding evaluation can be made with regard to the parts that are OK and those that are not. In step S90, the feed length for the blank 22 to be separated from the strip material 3 can be calculated at the same time or time-shifted.

In the subsequent step S100 the strip material 3 is fed to the separating device 19 by the two feed devices 15, 17 on the basis of the calculated feed length VL. While the strip material is fed forward by the calculated feed length VL for a first blank, the thickness and length measurement for the next blank 22′ to be cut out is carried out simultaneously by the thickness and length measuring devices 14, 16 in the region of the first feed unit 15. This is shown by the dashed line in FIG. 2. It is provided that the measuring distance between the thickness measurement 14 and the separating device 19 is set to at least twice the blank length L22 of a blank 22 to be cut out of the strip material 3 plus the feed path which the strip covers during the computing time for the blank to be cut out. The blank 22 is cut out in process step S110.

According to a further step S120 a further length measurement can be carried out by a second length measuring device 18 during the feed of the strip material 3 from the second feed device 17 to the separating unit 19. The second length measuring unit is arranged in the feed direction of the strip material 3 preferably directly behind the second feed device 17. It may also be provided as a further method step S130: comparing the first length measured values determined by the first length measuring device 16 with the associated second length measured values determined by the second length measuring device 18, and switching off the apparatus if a difference between the first and second length measured values exceeds a predetermined difference value. This measurement redundancy minimizes the risk of producing rejects.

FIGS. 3, 4 and 5 show various shapes of blanks to be produced from the strip material 3, and FIG. 6 shows an example of a separation sequence for a blank according to FIG. 3, respectively a blank according to FIG. 4.

FIG. 3 shows a rectangular blank 22 with an asymmetrical thickness D22 over the length L22 of the blank. Starting from the first end 23, the blank 22 has different sections 24 a, 24 b, 24 c, 24 d with different thicknesses D24 a, D24 b, D24 c, D24 d, wherein the first section 24 a and the last section 24 d at the second end 25 have the same thickness (D24 a=D24 d). Between each two sections 24 a, 24 b, 24 c, 24 d of constant thickness, which can also be referred to as plateaus, a transition section 26 a, 26 b, 26 c of variable thickness is formed, which can also be referred to as ramps. The rectangular blank 22 shown in FIG. 3 is produced by simply separating the strip material 3 brought to the correct position by the feeders 15, 17 by a simple cut, for example using a cross-cutting shear. An exemplary separation sequence for the rectangular blank 22 from FIG. 3 is shown in the upper path of FIG. 6. Successive blanks have the same reference sign with indices. There is an OK (“i.O.”) blank 22, followed by a not OK (“n.i.O.”) blank 28, followed by an OK (“i.O.”) blank 22, a short not OK (“n.i.O.”) intermediate piece 28 to be separated out, followed by another OK (“i.O.”) blank 22. The OK (“i.O.”) blanks 22, 22′, 22″ are stacked by a stacking system (not shown). The not OK (“n.i.O.”) sections 28, 28′ are automatically scrapped. The lower half of FIG. 6 shows another exemplary separation sequence for another exemplary rectangular blank. For the rectangular blanks 22, 22′, 22″ of the lower separation sequence, the thicknesses of the first section 24 a and the last section 24 a are also the same. The last section 24 a of the blank 22 has the same thickness as the first section 24 a′ of the following blank 22′. In the specific example shown, a not OK (“n.i.O.”) blank 28 is followed by an OK (“i.O”) blank 22, a short not OK (“n.i.O.”) intermediate piece 28 to be separated out, followed by another OK (“i.O.”) blank 22, a not OK (“n.i.O.”) blank 28″ and an OK (“i.O.”) blank 22″. The OK (“i.O”) blanks 22, 22′, 22″ are stacked by a stacking system (not shown). The not OK (“n.i.O.”) portions 28, 28′ are automatically scrapped.

FIG. 4 shows another embodiment of a rectangular blank 22, which, in contrast to FIG. 3, has a symmetrical thickness D22 over the length L22. It can be seen that the thickness profile D22 of blank 22 is mirror-symmetrical with respect to a middle plane E. The thickness profile D22 of blank 22 is mirror-symmetrical. The rectangular blank 22 shown here is also produced by simply cutting to length the strip material 3 brought to the correct position from the feeds 15, 17 by a simple cut, for example using a cross-cutting shear.

FIG. 5 shows an embodiment of blanks whose end sections each have a different thickness. For this reason, two successive blanks 22A, 22B are arranged mirrored to each other. A first blank 22A and a second blank 22B alternate along the length of the strip. The profile of the first blanks 22A corresponds to the profile of the second blanks 22B. The blanks 22A, 22B shown here also have an asymmetrical thickness profile D22A, D22B over the respective lengths L22A, L22B. It can be seen that the thickness profile D22A of the blank 22A is mirror symmetrical to the thickness profile D22B of the following blank 22B in relation to a center plane EAB. The blank 22A has, starting from the first end 23A, a first section 24Aa with a first thickness, a second section 24Ab with a second thickness, a third section 24Ac with a third thickness, a fourth section 24Ad with a fourth thickness and a last section 24Ae with a thickness unequal to the first thickness of the first section 24Aa. Between the sections 24Aa, 24Ab, 24Ac, 24Ad and 24Ae, each having a constant thickness over the length, transition sections 26Aa, 26Ab, 26Ac, 26Ad and 26Ae with variable thickness over the length are provided. The second blank 22B is designed symmetrically to the first blank. The second blank 22B is followed by a further first blank 22A, and so on. The rectangular blanks 22A, 22B shown here are also produced by simply cutting the strip material 3 brought into the correct position from the feeds 15, 17 by a simple cut, for example using a cross-cutting shear.

FIG. 7 shows an exemplary apparatus 2 for separating flexible rolled strip material in a modified embodiment. This corresponds to a widest extent to the embodiment shown in FIG. 1, so that reference is made to the above description with regard to the common features. The same and/or modified components are provided with the same reference signs as in FIG. 1. This apparatus 2 as shown in FIG. 7 can be operated using the same procedure described above in connection with FIG. 2.

The only difference in the present embodiment is the design of the separating device 19, which in this case comprises a form-cutting tool, in particular with a strip separating tool. The form-cutting tool is designed to cut a form cut blank 22 corresponding to the target contour out of the strip material 3. Depending on the component to be manufactured, one or more form cut blanks 22 can be cut out of strip material 3 in one operation of the form cutting tool. The separating device 19 can be designed as a punching tool, as shown in greater detail in FIG. 9, with a lower tool part 29 and an upper tool part 30 movable relative thereto to make a contoured cut. In addition, the separating device can have an integrated strip separating tool that separates a blank from the strip. The cutting sequence can be selected as required, i.e. first cutting a blank from the strip, then form cutting of the blank, or separation cutting and form cutting simultaneously, or first form cutting from the strip and then separation cutting from the strip. Analogous to the embodiment with cross-cutting shears, the present embodiment with form-cutting tool also provides an exact positioning of the form cut blank 22 to be cut out, relative to tool 19 by the feed units 15, 17. The cutting tool may have a cutting line deviating from a perpendicular to the strip edge, which may be straight, oblique or curved. Depending on the shape of the form cut blanks to be cut, sloping or curved cutting lines can be used to reduce punched scrap, as the case may be.

The feed units 15, 17 are control connected to the form cutting tool 19 in such a way that the strip material is fed in the desired length up to a reference point 32, respectively a reference plane at the form cutting tool 19. In particular, it is provided that the form cutting tool 19 be aligned exactly with respect to the press table 31 and be positioned and/or fixed exactly by means of positioning means, such as fitting pins or fitting cones for example.

FIG. 8 shows a form cut blank 22, which can be cut out using the punching tool 19 as shown in FIG. 7. The form cut blank 22 is characterized in that it has a defined circumferential contour 27. The contour of the sheet blanks 22 to be cut out of the strip material 3 is arbitrary and can be configured individually according to the geometric specifications. As an alternative to the punching tool described above, a beam cutting device is particularly suitable for producing a form cut blank 22, for example a laser beam cutting device, which can be moved along several axes, namely at least in the feed direction and in the transverse direction and, as the case may be, in the vertical direction of the strip material. The form cut blank 22 has sections 24 a, 24 b, 24 c, 24 d with different thicknesses (plateaus) and intermediate transition sections 26 a, 26 b, 26 c (ramps). FIG. 8 shows the reference edge 32 on which the strip material 3 is positioned in the separating device 19 to produce the form cut.

FIG. 9 shows an exemplary separation sequence for a form cut blank 22 from FIG. 8 by the form cutting tool 19, which is shown dashed here. Of the form cutting tool 19, the lower tool part 29, which is positioned on the press table 31, and the upper tool part 30 can be seen. For the cutting process, the strip 3 is advanced to a reference separating edge 32 according to the calculation of the feed unit 15, 17. Then, the form cut blank 22 is cut out by moving the upper part 30 to the lower part 29. The specifically shown example sequence comprises an OK (“i.O.”) form cut blank 22, followed by an OK (“i.O.”) blank portion 22 to be cut out, followed by two not OK (“n.i.O.”) blank portions 28, 28′, a further OK (“i.O.”) blank portion 22″, a further not OK (“n.i.O”) blank portion 28″, and a further OK (“i.O.”) blank portion 28″′. The OK (“i.O.”) blanks 22, 22′, 22″, 22′″ are stacked by means of a stacking system (not shown). The not OK (“n.i.O.”) portions 28, 28′ are automatically scrapped.

With the apparatus and, respectively, process described above, it is possible to uncoil coils 4 of flexibly rolled strip material 3, straighten them, examine the provided sheet thickness profiles for conformity with the sheet thickness tolerance and carry out an OK/not OK evaluation. By this, the strip 3 is divided into feed lengths, which are positioned exactly under the separating edge of the separating device 19. The cutting device 19 then cuts the feed lengths from the strip. In the case that the feed length is “OK” (i.O.), the rectangular or form cut blank is fed for further processing. If it is a feed length that is “not OK” (n.i.O.”), it is sorted out and scrapped.

LIST OF REFERENCE SIGNS

-   2 apparatus -   3 strip material -   4 coil -   5 coiler -   6 straightening unit -   7 inlet driver -   8 take-off roller -   9 buffer device -   10 uncoiling and straightening group -   12 separating group -   13 level sensor -   14 thickness measuring device -   15 first feed device -   16 first length measuring device -   17 second feed device -   18 second length measuring device -   19 separating device -   20, 20′ measuring wheel -   21, 21′ support wheel -   22 blank -   23 end -   24 sections -   25 end -   26 transition section -   27 circumferential contour -   28 not OK (n.i.O.) range -   29 lower tool part -   30 upper tool part -   31 press table -   32 reference edge -   A distance -   B trigger signal -   D thickness -   E plane -   L length -   M torque -   P profile -   R direction -   S step -   VL feed length 

1.-15. (canceled)
 16. An apparatus for separating flexibly rolled strip material, comprising: a buffer device arranged to temporarily buffer the flexibly rolled strip material; a first feed device which is arranged in feed direction of the strip material behind the buffer device; at least one length measuring device configured to continuously measure a length of the strip material; a thickness measuring device configured to continuously measure a thickness of the strip material along the length; a second feed device arranged behind the first feed device; and a separating device which is arranged in the feed direction of the strip material behind the second feed device; wherein the first feed device and the second feed device are configured to move the strip material depending on a thickness measurement and a length measurement from the buffer device to the separating device; wherein the thickness measuring device is arranged in the feed direction of the strip material between the buffer device and the first feed device; and wherein the at least one length measuring device is arranged in the feed direction of the strip material behind the first feed device.
 17. The apparatus of claim 16, wherein a coiler for uncoiling the flexibly rolled strip material and a straightening unit for straightening the flexibly rolled strip material are provided, which are arranged upstream of the buffer device, wherein the first feed device and the second feed device for the separating device are controlled independent of a feed of the coiler and the straightening unit.
 18. The apparatus of claim 16, wherein the at least one length measuring device comprises a measuring wheel which is in contact with a first side of the strip material, and a support wheel which is in contact as a counter-bearing for the measuring wheel with an opposite side of the strip material, wherein a running surface of the measuring wheel is made from a steel material.
 19. The apparatus of claim 16, wherein the at least one length measuring device comprises a first length measuring device for measuring the length of the strip material, and a second length measuring device for measuring the length of the strip material, wherein the second length measuring device is arranged in the feed direction of the strip material between the second feed device and the separating device.
 20. The apparatus of claim 19, wherein the first length measuring device has a first distance to the first feed device which is smaller than 0.5 times a distance between the first feed device and the second feed device, and wherein the second length measuring device has a second distance to the second feed device which is smaller than 0.5 times a distance between the second feed device and the separating device.
 21. The apparatus of claim 16, wherein the second feed device is drivable faster than the first feed device, so that the strip material is tension loaded between the first feed device and the second feed device.
 22. The apparatus of claim 16, wherein a distance between the thickness measuring device and the separating device is at least twice a blank length of a blank to be cut out of the strip material.
 23. The apparatus of claim 16, wherein the at least one length measuring device and the thickness measuring device are measuring technically coupled to one another, wherein the length measuring device generates trigger signals and transmits them to the thickness measuring device, with the trigger signals serving as triggers for carrying out thickness measurements.
 24. The apparatus of claim 16, wherein the separating device comprises a cross-cutting shear or a laser cutting unit.
 25. A method for separating flexibly rolled strip material, by an apparatus comprising a buffer device arranged to temporarily buffer the flexibly rolled strip material; a first feed device which is arranged behind the buffer device in feed direction of the strip material; at least one length measuring device configured to continuously measure a length of the strip material; a thickness measuring device configured to continuously measure a thickness of the strip material along the length; a second feed device arranged behind the first feed device; and a separating device which is arranged behind the second feed device in the feed direction of the strip material; wherein the first feed device and the second feed device are configured to move the strip material depending on a thickness measurement and a length measurement from the buffer device to the separating device; wherein the thickness measuring device is arranged, in the feed direction of the strip material, between the buffer device and the first feed device; and wherein the at least one length measuring device is arranged, in the feed direction of the strip material, behind the first feed device; the method comprising: performing intermediate buffering of the flexibly rolled strip material by the buffer device; advancing the strip material from the buffer device by the first feed device and the second feed device; continuously measuring a thickness of the strip material by the thickness measuring device while the strip material is being fed forward, wherein the measuring of the thickness takes place in the feed direction of the strip material upstream of the first feed device; continuously measuring a length of the strip material by the length measuring device while the strip material is being fed forward, the length being measured in the feed direction of the strip material behind the first feed device; calculating an actual thickness profile for a blank to be separated from the strip material from measured thickness values and associated measured length values; comparing the calculated actual thickness profile with a predetermined nominal thickness profile and calculating a feed length for the blank to be separated from the strip material; and feeding the strip material to the separating device by the first feed device and the second feed device on the basis of the calculated feed length.
 26. The method of claim 25, further comprising: continuously measuring the length of the strip material by the second length measuring device during the feeding of the strip material to the separating device, wherein the continuous measuring takes place by the second length measuring device in the feed direction of the strip material behind the second feed device; comparing the first length measured values determined by the first length measuring device with the associated second length measured values determined by the second length measuring device; and switching off the apparatus if a difference between the first length measured values and the second length measured values exceeds a specified difference value.
 27. The method of claim 25, wherein the first length measuring device is referenced at a starting point with the thickness measuring device with respect to the length, wherein the length measuring device generates trigger signals and transmits them to the thickness measuring device, with the trigger signals serving as triggers for carrying out thickness measurements by the thickness measuring device.
 28. The method of claim 25, wherein the first feed device and the second feed device are operated synchronously.
 29. The method of claim 25, wherein the first feed device and the second feed device are controlled such that the second feed device runs faster relative to the first feed device, so that the strip material is subjected to a tensile load.
 30. The method of claim 25, wherein a fixed first distance is set between the thickness measuring device and the first feed device, wherein a fixed second distance is set between the thickness measuring device and the separating device, and wherein at least one of the first distance and the second distance are measured with an accuracy of up to +/−0.2 mm. 